Non-adherence to antiretroviral medications can lead to the development of treatment resistant genetic variants of HIV, which can then be transmitted to sexual risk partners. This application proposes to test a theory-based behavioral intervention to simultaneously improve HIV treatment adherence and reduce HIV transmission risk behaviors in people living with HIV-AIDS. Grounded in the Information - Motivation - Behavioral Skills (1MB) model of health behavior change, the experimental intervention will be delivered in a mixed format model with four group sessions followed by two individual counseling sessions conducted by community-based group facilitators. The intervention will be conducted at an AIDS service organization in Atlanta. Men (n = 225) and women (n = 225) will be recruited from a variety of AIDS services and infectious disease clinics. Following informed consent and baseline assessments, participants will be randomly assigned to receive either the (a) integrated HIV treatment adherence - risk reduction intervention or (b) a time matched non-contaminating standard of care comparison intervention. Participants will be followed over the course of a 12-month observation period. Assessments will include measures of information, motivation, and behavioral skills pertaining to HIV treatment adherence and HIV transmission risks and risk reduction, self-report and objectively assessed medication adherence, sexual transmission risk behaviors, and viral load, and CD4 cell counts. The study will test the hypothesis that a unified, integrated theory-based HIV treatment and risk reduction intervention will improve HIV treatment adherence, reduce HIV transmission risk behaviors, and improve health. The study will also examine the influence of 1MB theoretical constructs on intervention outcomes. Changes in behavior that coincide with and predict maintenance of change and relapse to non-adherence and risk behaviors in relation to changes in viral load over the 12-month follow-up period will also be a focal point of the study. The intervention under investigation will be among the first to simultaneously address treatment adherence and sexual risk behavior in an integrated model derived from a single, unified theory of health behavior. If shown effective, the intervention model will have implications for community and clinical services for people living with HIV-AIDS.